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Foreword
Sleep is a basic necessity but it is only
in the last 40 years that we have begun
to understand more about sleep and
sleep disorders, through clinical and
basic sleep research. We now know
that sleep deprivation and sleep
disorders can affect quality of life, lead
to adverse medical consequences and
early mortality.
At SGH Sleep Disorders Unit, we have
the largest pool of internationally
trained and qualified sleep specialists,
offering a multidisciplinary set-up
for the effective management of
various sleep disorders for patients in
Singapore. We are also well-supported
by our internationally-accredited
sleep laboratory.
In this booklet, we will introduce
common sleep disorders to you, with
their symptoms, and what you can do
to help yourself. We want to empower
you to understand your conditions,
know when and where to seek
treatment.
KKH is a key referral centre for
sleep-related breathing disorders and
sleep disorders for children, where its
sleep specialists care for children up to
16 years of age.
At SingHealth, we offer a
comprehensive range of services for
diagnosis and management of both
adult and paediatric sleep disorders at
Singapore General Hospital (SGH) and
KK Women’s and Children’s Hospital
(KKH), respectively.
Our mission is to achieve the best
clinical outcomes for patients
suffering from sleep disorders,
because Sleep Matters.
Dr Toh Song Tar
Director, Sleep Disorders Unit
Consultant, Department of Otolaryngology
Singapore General Hospital
3
Contents
5
Normal sleep physiology (adults and seniors)
8
Sleep deprivation
10 Excessive daytime sleepiness
15 Sleep-disordered breathing and snoring
21 Obstructive sleep apnoea
25 Treatment for snoring and obstructive sleep apnoea
33Insomnia
37 Jet lag, shift work and circadian rhythm disorders
43 Movement disorders in sleep
48Sleepwalking
51 Sleepy driving
55 Common sleep conditions in infants, children and adolescents
71 Services available at SingHealth institutions
76Acknowledgements
Singapore Health Services Pte Ltd. All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical,
photocopying, recording or otherwise, without prior written permission from the copyright owner.
4
Normal sleep physiology
(adults and seniors)
Sleep is something that
we all do as naturally as
breathing and eating, from
the time you are formed in
utero till the time you die.
Yet scientists and doctors
understand the physiology
of breathing and eating far
better than we understand
the mysteries of the mind
and body during sleep.
In the last 20 years however, we are
beginning to understand far more
about sleep, both the physiology of
what happens as we fall asleep, and the
pathologies that underlie conditions
such as obstructive sleep apnoea
and its contribution to morbidity and
mortality.
Sleep is a period of time when the
body rests. As you fall asleep, the
brain begins to filter out sounds,
sights and other sensory input from
the surroundings. The muscle tone
gradually relaxes, allowing the body to
rest. Scientists divide normal sleep into
several stages, using differences in the
brain wave patterns and muscle tone to
differentiate the stages.
Stages of Sleep
Stage N1. This is a ’light’ stage of
sleep, where the brain’s sensory input
is shutting down but you may still be
able to hear and remember sounds
and other sensory inputs from the
surroundings.
It is common to drift in and out of
stage N1 sleep before falling deeper
into more consolidated stages of sleep.
A sleep-deprived person may have
episodes or microsleep where brief
periods (a few seconds) of N1 sleep
are interspersed during wake periods
without the person being aware of this.
These brief periods of microsleep can
be dangerous, for instance, in a driver
who ’switches off’ without realising it
5
while driving. Many people who have
trouble sleeping are actually drifting
in and out of stage N1 sleep without
realising it.
Stage N2. As you fall deeper into
sleep, the filtering of sensory inputs
intensifies. For instance, it will require a
louder sound to wake you up from N2
sleep than N1 sleep. The muscle tone in
the body drops and the body starts to
relax more.
When a person’s brain wave activity
is tracked as he falls asleep, certain
characteristic patterns during this
stage of sleep called spindles and
K-complexes can be seen.
Stage N3. Here you are deeply asleep.
It takes more effort to wake you up
from N3 sleep. On awakening at this
stage, you may report that you were
having a dream, although the images
and memories of dreams in N3 sleep
are usually more indistinct.
REM (Rapid Eye Movement) sleep.
This is a very interesting stage of sleep,
and usually occurs sequentially after
you have gone through the first three
stages of sleep. In this stage, your
6
muscle tone is very flaccid, and the
voluntary muscles e.g. arms and legs
are essentially paralysed. However,
there are bursts of eye movements
during REM sleep, hence this is called
Rapid Eye Movement sleep. In this stage
of sleep, both breathing and heart rate
become less regular.
In people with underlying heart and
lung disease, the oxygen levels in the
body can fall to very low levels. Despite
the inactivity seen in the muscles, there
is actually increased brain wave activity,
and when you wake from REM sleep,
you may report very vivid dreams.
How much sleep do you need?
An average adult sleeps about 7 hours
a night. However, there is a wide range
of normality with some people needing
only 4 hours and others needing up to
10 hours.
Some epidemiological studies suggest
that people who sleep too little or
too much may have more medical
problems or a higher mortality rate,
although whether this is a cause or
effect is debatable.
Normal sleep physiology (adults and seniors)
For most people, a clue to if you are
getting enough sleep is whether you
find yourself sleeping a lot more over
weekends or on holiday when you have
less restrictions on when you need to
get up. If you are sleeping a lot more
whenever you have the chance, and
you have a lot of lethargy or daytime
sleepiness, chances are you are not
sleeping enough to meet your body’s
requirements.
Over the course of a night, most
people go through four to five
complete cycles of sleep. They
drift from stage N1 to N2, to N3
sleep, into REM sleep, and then
go back to N1 sleep again. As the
night wears on, the length of the
REM sleep periods increases, with
the longest REM sleep period
often occurring just before they
wake up.
The quality of sleep also matters –
in certain medical conditions and
in certain sleep conditions such as
obstructive sleep apnoea, there is
disruption in this sleep cycle, resulting
in poor quality, unrefreshed sleep.
Most adults need about 7 hours of sleep, although the norm can vary.
7
Sleep deprivation
Sleep deprivation is a
condition where someone is
not getting enough sleep; it
can either be chronic or acute.
The absolute number of hours of sleep
necessary for someone to function
properly is not known. Some people
can function with full effectiveness with
only three to five hours of sleep per
night, while others need at least eight
hours or more of sleep per night.
A chronically sleep-deprived state can
cause tiredness, excessive daytime
sleepiness, clumsiness and weight gain.
It impairs the normal functioning of
the brain. It is impossible for humans
to go completely without sleep for
long periods of time - brief microsleeps
cannot be avoided. Total sleep
deprivation has been shown to cause
death in lab animals.
What are microsleeps?
Microsleeps occur when someone is
significantly sleep-deprived. The brain
8
can automatically shut down, falling
into a sleep state that can last from a
second to half a minute.
You can fall asleep no matter what you
are doing. Microsleeps are similar to
blackouts and you will not be aware
that they are occurring when you are
experiencing them.
Effects of sleep deprivation
Individuals who are sleep-deprived may
not recognise the effects of being so.
Small amounts of sleep loss over many
The effects of sleep loss are often unrecognised.
Sleep deprivation
nights may result in subtle cognitive loss,
which appears to go unrecognised by
the individual.
More severe sleep deprivation for a
week can lead to profound cognitive
dysfunction similar to those seen in
some stroke patients, which may also
appear to go unrecognised by the
individual.
Sleep deprivation can cause:
• Confusion, memory lapses
• Depression, irritability, headaches
• Eye bags and bloodshot eyes
• Increased blood pressure, increased
stress hormone level
• Increased risk of diabetes, obesity
• Decreased immunity
• Decreased growth hormones
• Increased risk of road traffic accidents
• Poor work productivity
• Poor quality of life
• Sleeping less than four hours a night
is associated with higher risk of
premature death
Prevention
Maintain proper sleep hygiene.
Seek medical help if you feel that
you are not sleeping well.
Causes
Lifestyle
You may choose not to sleep to watch
a midnight show, talk to friends, play
computer or video games.
Heavy work commitment and stress
may hinder sleep and lead to sleep
deprivation.
Shift workers may be affected by sleep
deprivation.
Medical disorders
Many medical conditions can lead
to sleeplessness and hence sleep
deprivation.
Chronic pains and aches can lead to
disturbed sleep and sleep deprivation.
Sleep disorders like obstructive sleep
apnoea, narcolepsy, and restless legs
syndrome can lead to disruption of
normal sleeping pattern and sleep
deprivation.
Nasal obstruction can result in
someone not being able to sleep,
therefore being sleep-deprived.
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
9
Excessive daytime sleepiness
Excessive daytime sleepiness
refers to the inability to stay
alert during the major awake
period of the day, resulting
in you falling asleep at
inappropriate times. When
sleepiness interferes with
daily routines and activities,
or reduces your ability to
function, it is considered
excessive.
This is a prevalent condition. In
Singapore, the prevalence of
excessive daytime sleepiness has
been reported to be 9 percent
(Ng TP et al, Sleep Medicine 2005).
A ‘sleep debt’ builds until enough sleep is obtained.
10
Causes
Causes of excessive daytime sleepiness
include the following. It is commonly
caused by more than one of these
causes.
1. Inadequate sleep
The amount of sleep needed each
night varies amongst different people.
Excessive daytime sleepiness
Most need seven to eight hours of
uninterrupted sleep to maintain
alertness the following day. A habitual
sleep period of less than four to five
hours daily is generally insufficient to
maintain normal daytime alertness
and is likely to cause excessive daytime
sleepiness.
If you do not get enough sleep
even on a single night, a ’sleep debt’
begins to build and increases until
sufficient sleep is obtained. Excessive
daytime sleepiness occurs as the debt
accumulates. If you do not get enough
sleep during the work week, you may
tend to sleep longer on the weekends
or days off to reduce your sleep debt.
2. Disorders affecting sleep
Disorders such as obstructive sleep
apnoea, narcolepsy, restless legs
syndrome, periodic limb movement
disorder and insomnia may cause
excessive daytime sleepiness.
• Obstructive sleep apnoea is a
potentially serious disorder in
which your breathing is interrupted
during sleep. This causes you to
awaken many times during the
night and experience excessive
daytime sleepiness.
• Narcolepsy will cause excessive
daytime sleepiness during the day,
even after getting sufficient sleep
at night. You may fall asleep at
inappropriate times and places.
• Restless legs syndrome causes a
person to experience unpleasant
sensations in the legs. These
sensations frequently occur in the
evening, making it difficult for you
to fall asleep, leading to excessive
daytime sleepiness.
• Periodic limb movement disorder
is a sleep disorder where there is
involuntary limb movement during
sleep, leading to excessive daytime
sleepiness, difficulty falling asleep
at night or difficulty staying asleep
throughout the night.
• Insomnia is the perception of poor
quality sleep due to difficulty falling
asleep, waking up during the night
with difficulty returning to sleep or
waking up too early in the morning.
3. Medications
Some medications may disrupt sleep
and cause sleepiness. Examples
include sedating antihistamines,
sedatives, antidepressants and seizure
medications.
11
4. Alcohol
Alcohol is sedating and can, even in
small amounts, make a person more
sleepy and at greater risk of car crashes
and performance problems.
5. Caffeine
Caffeine in coffee, tea, soft drinks or
medications makes it harder for many
people to fall asleep and stay asleep.
Caffeine stays in the body for about
three to seven hours, so even when
taken earlier in the day, it may cause
problems in falling asleep at night.
Caffeine stays in the body for 3 to 7 hours.
6. Nicotine
Nicotine from cigarettes is also a
stimulant and makes it harder to fall
asleep and stay asleep.
12
7. Medical conditions
Chronic medical conditions such as
asthma, heart failure, depression,
Parkinson’s disease, rheumatoid
arthritis or any other chronically painful
disorder may also disrupt sleep and
lead to excessive daytime sleepiness.
Excessive daytime sleepiness may also
occur following head injury and rarely,
due to brain tumour.
8. Sleep-wake cycle disturbance
(such as shift work)
Most shift workers get less sleep over
24 hours as compared to day workers.
The human sleep-wake system is
designed to facilitate the body and
mind for sleep at night and wakefulness
during the day. These natural rhythms
make it difficult to sleep during daylight
hours and to stay awake during the
night hours, even in well-rested
individuals.
Sleep loss is greatest for night shift
workers, those who work early morning
shifts and female shift workers with
children at home. Shift workers who
try to sleep during the day are
frequently interrupted by noise, light,
the telephone, family members and
other distractions.
Excessive daytime sleepiness
Get help if you feel sleepy despite getting enough sleep.
Symptoms
Diagnosis
Signs of excessive daytime sleepiness
may include:
If you feel sleepy during the day despite
getting enough sleep, consult your
physician who will evaluate the possible
causes and advise on the appropriate
management. It is important to get
proper diagnosis and treatment of the
underlying cause of the sleepiness.
Your physician may refer you to a sleep
disorders clinic for a comprehensive
evaluation of your problem.
• Difficulty paying attention or
•
•
•
•
•
•
concentrating at work, school or
home
Poor performance at work or school
Difficulty in staying awake when
inactive, such as when watching
television or reading
Difficulty remembering things
Need to take naps on most days
Sleepiness that is noticed by others
Falling asleep while driving
13
Management
Identifying the cause(s) of excessive
daytime sleepiness is the key to its
management. Treatment is directed
towards the specific underlying cause.
Obstructive sleep apnoea is generally
treated with Continuous Positive Airway
Pressure (CPAP).
In general, medications do not
help problem sleepiness and some
medications may make it worse.
Medications may be prescribed for
patients in certain situations.
Short-term use of sleeping pills has
been shown to be helpful in patients
diagnosed with acute insomnia.
Long-term use of sleep medication is
recommended only for treatment of
specific sleep disorders. Stimulants
to maintain alertness are used in the
treatment of narcolepsy.
Self/Home care
• Get enough sleep
Many people do not set aside
enough time for sleep on a
regular basis. A first step may be
to evaluate your daily activities
and sleep-wake patterns to
determine how much sleep is
obtained. If you are getting less
14
than 8 hours of sleep, more sleep
may be needed.
A good approach is to gradually
move to an earlier bedtime.
For example, if an extra hour of
sleep is needed, try going to bed
15 minutes earlier each night for
four nights, then keep to the last
bedtime. This method will
increase the amount of time in
bed without causing a sudden
change in schedule.
• Avoid caffeine
Avoid beverages containing
caffeine (coffee, tea and some
soft drinks). Caffeine can help to
reduce sleepiness and increase
alertness but the effect is
temporary. It can cause problem
sleepiness to become worse by
interrupting sleep.
• Avoid alcohol
While alcohol may shorten the time
it takes to fall asleep, it can disrupt
sleep later in the night, leading to
poor quality sleep and adding to
problem sleepiness. Chronic use of
larger quantities of alcohol can also
lead to alcohol dependency.
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
Sleep-disordered
breathing and snoring
Sleep-disordered breathing
refers to a spectrum of
conditions characterised
by abnormal breathing
during sleep. This can range
from mild simple snoring to
Obstructive Sleep Apnoea (OSA).
In simple snoring, there is mild
narrowing of the upper airways
causing noisy breathing during sleep
but no associated sleep disturbance
or impairment of daytime function.
In contrast, patients with OSA have
more severe airway obstruction during
sleep which results in significant
sleep disturbance, repeated cycles of
low oxygenation and impairment of
daytime function.
In a local study, approximately 24
percent of adults are loud habitual
snorers and about 15 percent of
adults are estimated to have OSA
(Puvanendran K et al, Sleep Research
Online 1999).
Not everyone who snores has obstructive sleep apnoea.
15
Causes
Snoring is caused by the vibration or
flapping of tissues lining the upper air
passages. This may be due to:
• Relaxation of muscles causing
the walls of the upper airway to fall
together, causing them to vibrate.
• Swelling of the tissue in the walls,
for example, due to anatomical or
injury, which may cause narrowing.
• The tongue falls back into the
throat when sleeping on the back,
contributing to the snoring.
• Nasal blockages such as nasal
allergy or deformities of the nasal
septum (the cartilage partition
between the two sides of the nose)
which can cause poor nasal airflow
and set the soft tissues of the palate
(roof of the mouth) and throat
vibrating.
Individuals with OSA have a narrower
and more collapsible upper airway
causing repeated upper airway
obstruction during sleep. When
breathing stops, the level of oxygen in
the bloodstream falls. The brain senses
this decrease in oxygen and rouses the
person from sleep. With awakening,
the muscles at the back of the throat
16
become more active and hold the
airway open so that breathing can
resume.
Symptoms
Soft, rhythmic snoring is not believed
to have any significant adverse health
effects.
However, when snoring becomes loud,
breathing may be impaired and sleep
disrupted.
The repeated awakenings make
it hard to get a good night’s
sleep, resulting in poor sleep
quality and sleep deprivation.
The upper airway obstruction
leads to decreased oxygen
supply to the brain, heart
and other organs and puts
tremendous stress on the heart
and body, leading to medical
consequences in the long run.
Someone with OSA may present
with loud and habitual snoring,
excessive daytime sleepiness, feeling
unrefreshed despite adequate sleep
hours, falling asleep while driving,
depression, irritation, decreased libido
Sleep-disordered breathing and snoring
and morning headaches. Their sleep
partners may also notice gasping and
choking episodes during sleep. As the
lack of sleep is very stressful, affected
individuals may become irritable,
undergo changes in personality, or
have difficulty with memory.
Untreated OSA may lead to high
blood pressure. There are also higher
incidences of ischaemic heart disease,
irregular heart rhythm and strokes
in individuals with OSA. When OSA
is severe, heart failure may occur.
Untreated OSA is also associated with
increased risk of sudden death and
premature death.
Risk factors
Any condition that contributes to the
narrowing at the back of the throat
such as enlarged tonsils or adenoids
favour the development of OSA.
Large tonsils are the most common
cause of snoring and sleep apnoea in
infants. They can also be the occasional
cause of problems in adults although
nasal and soft palate problems are the
more common causes of adult snoring.
Other factors which may influence
the snoring condition and the
development of OSA are obesity,
Snoring and obstructive sleep apnoea are more common in males.
17
ageing and associated loss of general
muscle tone, throat congestion due
to reflux of stomach acid (heartburn);
and the effects of alcohol, sedatives
and smoking.
significant snoring, sleep apnoea
needs to be ruled out. The evaluation
usually involves an overnight
monitoring of sleep, called a sleep
study or polysomnogram.
In obesity, excessive fat accumulation
in the upper airway may amplify
an existing anatomic narrowing of
the upper airway that was causing
minimal obstruction previously.
A sleep study records the number
of irregular breathing events and
their duration, the oxygen levels in
the blood (measured by a device
placed on the finger), the heartbeat,
the snoring pattern, the amount and
quality of sleep as well as the effect of
sleeping positions on breathing.
Snoring and OSA are also more
common among males and
in individuals with a genetic
predisposition leading to facial and
jaw abnormalities.
Diagnosis
Consult your physician if you have
loud snoring or excessive daytime
sleepiness despite getting enough
sleep. Your physician will evaluate the
possible causes and advise on the
appropriate management.
Your physician may refer you
to a sleep disorders clinic for a
comprehensive evaluation of your
problem. A thorough examination
of the nose, mouth, throat and neck
is performed. In someone with
18
Medications are not effective in treating obstructive
sleep apnoea.
Treatment
Effective treatment is available for
almost all patients. Treatment of
both snoring and OSA requires a
multidisciplinary approach.
Sleep-disordered breathing and snoring
1. Treatment for snoring
The treatment of snoring is divided
into medical and surgical options. The
treatment choice is individualised. In
the treatment of snoring, a ’staged’
approach is often used, which
generally involves medical therapy
first, followed by consideration
of surgery, if medical therapy is
unsuccessful.
Medical
For patients with snoring and mild
OSA, a conservative approach is
usually recommended.
Surgical
Surgical procedures for the treatment
of snoring may include nasal, palatal,
jaw, tongue and neck surgery. The
surgical procedure recommended will
depend on the location of the tissues
contributing to the snoring.
2. Treatment for OSA
Indications for treatment of OSA
include excessive daytime sleepiness
affecting daytime performance,
moderate to severe OSA and
cardiovascular complications
(hypertension, ischaemic heart disease,
irregular heart rhythm and stroke).
These include:
• Weight loss
• Avoidance of alcohol
• Sedative medications. Sedatives
relax the muscles at the back of the
throat and may depress breathing.
• Nasal congestion is also treated
with medications. Nasal obstruction
increases the frequency of snoring
and disordered breathing during
sleep.
• Sleeping on the sides rather than
on the back. This position prevents
the tongue and soft palate from
collapsing against the back of the
throat and blocking the airway.
Treatment of OSA can improve
daytime sleepiness, prevent
cardiovascular complications, decrease
sleep apnoea-related road traffic and
workplace accidents, and improve
quality of life.
A medical device called Continuous
Positive Airway Pressure (CPAP)
may be recommended for patients
with moderate to severe OSA. This
device delivers room air to the nose
and back of the throat at a slightly
elevated pressure to prevent the
airway from collapsing during sleep.
CPAP is safe, generally well-tolerated
19
and highly effective. This device
must be worn nightly and long-term
CPAP compliance is essential for its
effectiveness.
Dental appliances that reposition
the lower jaw and tongue have been
helpful in some patients with mild OSA
and snoring. Dental appliances have to
be worn every night. Dental and lower
jaw joint side effects may prevent
compliance.
Surgery may be recommended for
treatment of OSA for some individuals.
Surgery is individualised and may
range from procedures designed to
open the nose and enlarge the back of
the throat. Medications are ineffective
in treating OSA.
Self/Home care
Some useful suggestions for
snorers:
• Reduce weight if you are obese.
• Avoid taking sleeping pills/
sedatives. Certain sleeping pills
may cause the upper airway to
relax, leading to snoring.
• Avoid consuming alcohol after
6pm. Alcohol causes relaxation
of muscles of the upper airway.
• Sleep on your side and avoid
sleeping on the back.
• Quit smoking. Smoking causes
swelling of the tissues of the
upper airway, which results in
snoring.
• Allow your bed partner to fall
asleep before retiring to bed.
• Provide earplugs for your bed
partner.
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
20
Obstructive sleep apnoea
Obstructive Sleep Apnoea
(OSA) is a condition in which
the upper airway collapses
repeatedly during sleep.
This creates an effect similar
to that of being repeatedly
choked throughout the night.
During these episodes, there are
recurrent dips in the blood oxygen
levels, putting stress on the heart.
As a result, sleep is unrefreshing and
patients typically feel sleepy and
irritable throughout the day.
What if OSA is left untreated?
In addition to causing sleep disruption
and daytime symptoms, OSA can
increase the risks of serious health
complications such as:
• Memory loss
• Stroke (Almost 70 percent of people
•
•
•
•
•
Even a short sleep arousal can lead to unrefreshing
sleep.
•
who have had a stroke have OSA)
Hypertension (>35 percent of
people with sleep apnoea suffer
from hypertension)
Diabetes
Depression
Heart failure and heart attacks
(by 2 to 3 times)
Risk of motor vehicle accidents
(by 7 times)
Increased risk of work-related
accidents
21
Symptoms
• Loud, frequent snoring
• Cessation of breathing or gasping
•
•
•
•
for air during sleep
Excessive daytime sleepiness
Unrefreshing sleep
Frequent urination at night
Erectile dysfunction
I sleep through the night without
recurrent awakenings, does this mean
I do not have OSA?
No. Often, the sleep disturbances
caused by OSA are short and
intermittent and are insufficient to
fully rouse the affected person from
sleep completely. These repeated
short arousals are however enough to
result in unrefreshing sleep and all the
adverse health consequences described
previously.
Diagnosis
What is a sleep study?
A sleep study or polysomnogram
(PSG) is an overnight noninvasive
diagnostic test done in a Sleep
Laboratory. The PSG monitors
the different stages of sleep,
heart rhythm, muscle activity,
breathing effort and oxygen
levels during sleep. The severity
of OSA can also be determined.
Treatment
A very effective treatment for OSA is
Continuous Positive Airway Pressure
(CPAP) therapy. CPAP therapy is
considered the gold standard and
most effective non-surgical treatment
for OSA. Depending on the severity of
OSA and the upper airway anatomy,
other treatment options include
weight loss, wearing of appliance
during sleep and surgery.
It is best to see a sleep specialist to
confirm the diagnosis. In the initial
consultation, a thorough sleep history
and examination will be undertaken to
assess for OSA. If OSA is suspected, an
overnight sleep study will be arranged
to confirm the diagnosis of OSA.
Continuous Positive Airway Pressure
22
Obstructive sleep apnoea
How does CPAP therapy work?
CPAP therapy works by quietly
delivering pressurised air through
the nose or mouth to keep the upper
airway open and maintain normal
breathing during sleep. There are two
important parts of the CPAP machine
that need to be decided on by careful
consultation with your sleep physician
prior to using CPAP.
They are:
1. The mask:
CPAP is administered through a mask
that seals either the nose, the mouth or
both. There are a variety of masks that
can be used. Most of these are made
from soft silicon or gel to maximise
comfort. The mask chosen for you will
be fitted by a sleep technician to suit
your facial structure and breathing
habits.
The first step in choosing the type of
mask is to establish how you breathe
naturally (through the nose, mouth
or both). There are different types of
masks to suit different needs, such as:
• Nasal masks (for nose breathers)
• Nasal pillows (for nose breathers)
• Full face masks (for nose and mouth
breathers)
• Oral-nasal masks (for nose and
mouth breathers)
• Oral masks (for mouth breathers)
In order to optimise the comfort and
success of CPAP therapy, it is important
to identify and treat any reversible
causes of nasal obstruction (e.g.
chronic rhinitis, nasal polyps or septal
deformities) prior to CPAP therapy.
2. The machine:
Most CPAP machines today are small –
about the size of a bedside alarm clock –
quiet and relatively portable.
Modern CPAP devices can deliver
a fixed pressure or may have
sophisticated software that can
detect obstruction and self-adjust
the delivered pressure (auto-titrating
machines). Excessive pressure can
cause air leak and discomfort while
insufficient pressure will not effectively
treat the sleep apnoea.
23
Some devices have special modes that
allow you to breathe out more easily,
or can deliver a different pressure
depending on whether you are
breathing in or out.
The type and setting of each device
will need to be individualised for each
patient after consultation with your
sleep specialist.
What happens after OSA is
treated?
OSA sufferers who start using
CPAP report sleeping better and
feeling more energetic and less
sleepy during the day. Some report
feeling better after the first day
of treatment while for others, the
improvement may only become
apparent after a few weeks of
sustained use. The benefits of
CPAP include:
• Improved sleep quality with
reduction or elimination of
snoring and apnoea
• Feeling more rested and alert
during the day with improved
memory and cognition
• Improved blood pressure control
• Reduced risks of stroke, heart
failure and heart attacks
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
24
Treatment for snoring and
obstructive sleep apnoea
Snoring and Obstructive Sleep
Apnoea (OSA) are common
medical conditions that affect
between 15-50% of the adult
population worldwide.
Snoring, due to vibration of tissues in
the throat, can be a symptom of partial
upper airway obstruction. The partial
obstruction can lead to complete
airway obstruction – a medical
condition called OSA. This obstruction
can occur anywhere along the course
of the upper airway and usually occurs
in the nose, in the oral pharynx behind
the soft palate or behind the base of
the tongue. In Singapore, about 15
percent of adults have OSA.
The upper airway from the nose to the windpipe. Common areas of obstruction are circled.
25
contribute to upper airway obstruction
during sleep. Identification of these
areas allows the surgery to be tailored
for that particular patient’s problem.
Normal airway
OSA airway
OSA treatment should be started if the
sufferer experiences excessive daytime
sleepiness with altered daytime
performance, moderate to severe OSA,
decreased blood oxygen saturation
level and cardiovascular complications.
The current first-line treatment of
OSA is with Continuous Positive
Airway Pressure (CPAP) which
requires wearing a mask that conveys
pressurised air to the patient’s airway
during sleep.
However, not all patients are able to
tolerate CPAP or are willing to try this
form of treatment. In these patients,
surgical treatment is indicated.
Surgical treatment planning
for OSA
If a patient opts for surgery, the
upper airway is examined with
nasoendoscopy performed by an
ENT specialist to look for areas that
26
Several options for surgery exist that
are directed at obstructions that may
occur at the level of the nasal airway,
soft palate or base of tongue.
Common problem areas of
obstruction
The area behind the soft palate is
the most common site of obstruction
that causes snoring and OSA. Hence,
most treatments are directed at this
area. Obstruction in this area can
be caused by excessively bulky and
floppy soft palate tissue or enlarged
tonsils. Surgical treatment of this area
would aim to reduce the bulkiness and
floppiness of the soft palate or remove
enlarged tonsils.
In the nose, normal structures
called turbinates may be enlarged
from allergic rhinitis causing airflow
blockage. The septum that divides
the nose into two sides may also be
deviated to one side, resulting in
reduced flow through that nostril.
Treatment for snoring and obstructive sleep apnoea
Options to relieve nasal airway
obstruction include reducing the size
of the turbinates and straightening
a deviated septum. An open nasal
airway establishes normal breathing
and minimises mouth breathing.
Radiofrequency of the soft palate.
Mouth breathing in OSA individuals
worsens the posterior airway by
allowing the tongue to fall back. In
addition, establishing an open nasal
airway passage can improve CPAP
comfort and compliance in those who
wish to continue using CPAP.
The base of tongue and lingual
tonsils (lymphatic tissues at the back
of the tongue) may be enlarged,
impeding airflow during sleep.
Obstruction at this site can be treated
by a variety of methods depending on
severity. Options include reducing the
size of the bulky tissue of the tongue
and/or lingual tonsils or shifting
the position of the base of tongue
forwards to reduce obstruction.
Types of surgery
Radiofrequency of the inferior turbinate.
Radiofrequency of the tongue base can reduce
tongue base obstruction.
Surgical procedures serve to remove
or reposition tissues that partially or
completely block the upper airway
during sleep. These procedures have
been used for years and clinical
outcomes have verified their use.
Tracheostomy
Tracheostomy involves creating a hole
in the trachea, directly bypassing the
upper airway obstruction. It is used in
people with refractory base of tongue
27
Nasal passage with sinuses
obstruction and in the morbidly
obese with medical conditions that
contraindicate surgeries that are more
extensive. Though the success rate is
100 percent, this option is usually not
accepted by patients and with the
introduction of CPAP, it is seldom used
to treat OSA.
Nasal Surgery
Nasal airway obstruction caused
by septum deviation or enlarged
turbinates can interfere with nasal
breathing during sleep. Options
to relieve nasal airway obstruction
include reducing the size of the
turbinates and straightening a
deviated septum.
Nasal septum and upper airway
28
Treatment for snoring and obstructive sleep apnoea
The turbinates can be reduced either
by radiofrequency ablation performed
under local anaesthesia in the clinic
setting or by surgical reduction under
general anaesthesia (turbinoplasty).
Correction of a deviated septum and
nasal valve reconstruction can also be
used to improve nasal patency.
Palatal Surgery
Abnormal structures at the palate level
include large tonsils, redundant lateral
pharyngeal mucosal, thick and long
soft palate and enlarged posterior
tonsillar pillar muscles and mucosal. All
these contribute to a narrow airway at
the palatal level.
Narrowed oropharyngeal airway with long soft palate
The traditional
Uvulopalatopharyngoplasty (UPPP)
and many variations of it can be
used. Most surgeons have shied
away from the traditional UPPP in
favour of modified techniques and
surgical flaps (like uvulopalatal flap,
extended uvulopalatal flap, lateral
pharyngoplasty) as these have fewer
complications, are less ablative and
have a higher success rate.
In carefully selected patients with
obstruction at the palate level, the
success rate may be 50 to 60 percent
but increases when combined with
other procedures that address nasal
and tongue base obstruction.
Enlarged oropharyngeal airway
Hypopharyngeal and Base of Tongue
Surgery
Compared to the nasal and
oropharyngeal level, obstruction at the
hypopharyngeal (base of tongue) level
is a very complex issue as the large
29
Genioplasty with genial tubercle advancement – tongue muscle is pulled forward to increase posterior airway
space and to increase tension of the tongue to reduce obstruction during sleep.
tongue base tissue collapses easily
during sleep.
Obstruction at this level may be
addressed by either increasing airway
size to make more room for the tongue
or reducing the tongue size. Both soft
tissue techniques and skeletal work
may be required. Soft tissue work
involves removing the mid-portion
of the tongue (median glossectomy,
lingualplasty or volumetric reduction
by radiofrequency). Transoral robotic
surgery can be used to access this area.
Skeletal advancement techniques
can increase the airway size and
tension on the tongue so that even
if the tongue falls back during sleep
it does not obstruct the airway. This
procedure includes inferior sagittal
mandibular osteotomy, genioglossus
advancement and hyoid suspension.
30
Combining nasal/palate and tongue
base surgery, the success rate can
reach 70 to 80 percent.
Maxillomandibular Advancement
Surgery
Maxillomandibular advancement
surgery is a more aggressive
procedure, usually saved for times
when more conservative surgery fails.
It involves the forward movement of
the lower jaw and mid-face and gives
the tongue more room, opens the
airway more and places additional
tension on the tongue base.
The individualised use of soft tissue
and skeletal procedures for upper
airway reconstruction ensures that the
most conservative treatment is offered
and the possibility of unnecessary
surgery reduced.
Treatment for snoring and obstructive sleep apnoea
In maxillomandibular advancement surgery the lower jaw and
mid-face is moved forward to increase posterior airway space.
Transoral Robotic Surgery (TORS) for
Obstructive Sleep Apnoea
The da Vinci robotic surgery system
allows the surgeon superior access
and view of the tongue base and
hypopharyngeal area not previously
possible. It allows the surgeon to
address airway obstruction secondary
to lingual tonsillar hypertrophy,
tongue base hypertrophy and floppy
epiglottis.
The da Vinci Transoral Robotic Surgery (TORS) for OSA
31
Hypoglossal Nerve Stimulation
Hypoglossal nerve stimulation is a
novel form of therapy that has been
shown to be effective in treating OSA
by increasing upper airway muscle
tone during sleep. This is achieved
by an implantable device implanted
beneath the skin in the chest that
is switched on by the patient just
before sleep. This device then applies
mild stimulation of the hypoglossal
nerve that supplies the tongue. The
rate of this stimulation is synced to
the patient’s breathing pattern to
achieve the optimal amount of tongue
protrusion needed to relieve tongue
base obstruction as the patient inhales
during sleep.
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
32
Insomnia
Insomnia is one of the
most common sleep
problems in the general
population. In Asia,
a survey of the South
Korean population
found that 17% had at
least three nights of
insomnia each week.
Another study in Hong
Kong found 11.9% with
insomnia.
Women, older people and worriers are at higher risk of insomnia.
Causes and Risk factors
There are many causes of insomnia
and it can be due to a single factor or
combination of factors. Women, older
people and worriers are at higher risk
of having insomnia.
Jetlag, shift work or a noisy sleeping
environment are common reasons for
insomnia.
Life stressors such as difficulties at
work or the death of loved ones can
also cause insomnia.
Unhealthy sleeping practices termed
as ’poor sleep hygiene’ can also result
in insomnia. Some examples include
drinking caffeinated drinks in the
evening. Some people may also take
frequent naps during the weekends
leading to insomnia on Sunday nights.
33
Insomnia can be a hint of a more
serious underlying psychiatric
condition such as depression or an
anxiety disorder.
This can, in turn, lead to feelings
of irritability, tiredness and poor
concentration. As a result, productivity
at work may dip. You may feel less
fulfilled and get less satisfaction from
hobbies and relationships.
Long-term misuse of medications
like sleeping pills or alcohol can also
result in insomnia.
Diagnosis
Health problems like physical
illnesses can also cause insomnia.
These conditions can be those that
result in pain (like chronic back pain)
or frequent urination (like enlarged
prostate gland in older men).
The doctor will take a full sleep history
from you and your sleeping partner,
if any. This may be followed by a
physical examination. Laboratory tests
including blood tests may also be
ordered.
Sometimes, no specific causes can
be pinpointed. These are termed as
’Primary Insomnia’.
In a specialist clinic dealing with sleep
disorders, the doctor may want to
admit you to observe the sleep to
see if specific medical conditions (e.g.
obstructive sleep apnoea where there
are abnormal pauses in breathing
during sleep) are suspected. This is
known as a sleep study.
Symptoms
You may have difficulty falling asleep,
frequent awakenings in the middle
of the night or waking up in the wee
hours of the morning. You may also
experience non-restorative sleep i.e.
feeling unrefreshed in the morning.
34
Insomnia
In the sleep history, the doctor may ask
for information on the following:
1. Duration: Whether the insomnia has
persisted for days, weeks or months
2. Frequency: How many days in the
week it occurs
3. Type: Whether you have difficulty
falling asleep, maintaining sleep or
experience early awakening
4. Environmental factors such as noise
level, whether the surroundings are
uncomfortable or if you work shifts
5. Evidence of poor sleeping habits
such as frequent naps, lying in bed
throughout the day or drinking
caffeinated drinks at night
Treatment
The doctor will deal with the
underlying causes that are working
together to cause the insomnia.
Behavioural Methods
The doctor may also employ
behavioural methods to improve sleep.
However, these methods require time
and effort to see results.
These methods include:
1. Good sleep hygiene
2. Relaxation techniques (e.g. deepbreathing exercises)
3.Hypnosis
4. Learning how to cope with stress
5. Engaging a trained therapist for
Cognitive Behavioural Therapy
Do not surf the internet in bed.
35
Medication
There are many different medications
for insomnia. These range from
milder ones like antihistamines (more
commonly used for the common
cold or itch) to stronger medications
that can also be used for anxiety
and depression. Lastly, there are
medications that are used purely for
sleep and some of these can be very
addictive. Therefore, this last category
of medication is usually used only for
short periods.
While medications can offer rapid
relief, they confer only short-term
benefits. Many of them also have
side effects. Some sleeping pills are
highly addictive. In elderly patients,
the drowsiness from the sleeping
pills can lead to a higher risk of falls.
This, in turn, leads to a higher risk of
hip fractures that have devastating
consequences for older people. The
doctor will advise you carefully before
starting you on these medications.
Sleep Hygiene Advice
Good sleep hygiene is a
behavioural method that can be
used to improve sleep. The sleep
hygiene advice listed below can be
easily practiced at home. However,
you may need to keep to them for
many days or even weeks before
any improvement can be seen.
They are:
1. Keep to the same sleeping
and waking time, even during
weekends
2. Exercise regularly but not three
to four hours before bedtime
3. Avoid taking naps
4. Avoid activities like reading or
surfing the internet in bed
5. Avoid caffeinated drinks like
coffee, tea or colas
6. Avoid heavy meals, alcohol or
smoking before sleep
7. Have a conducive sleep
environment that is cool and
quiet
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
36
Jet lag, shift work and
circadian rhythm disorders
Commonly known as the
‘body clock’, the circadian
rhythm is an innate cyclical
rhythm that regulates
many bodily functions
automatically throughout
the day, and does not require
conscious control.
There are those that are apparent to us,
such as the sleep-wake cycle and the
digestive cycle, for which we feel sleepy
or hungry when we reach a certain
time of the day. There are also those
that are not so obvious such as core
body temperature and the release of
hormones into the bloodstream.
In human beings, this innate rhythm
cycles between the duration of 24.2
to 24.9 hours, just slightly longer than
a day. This could potentially create
a messy situation where we could
fall asleep or need to eat at very
inconvenient timings, over a period of
time.
Fortunately, this ‘clock’ is synchronised
to the 24-hour day by environmental
inputs, most importantly by sunlight,
as well as by social rhythm such as
common meal times, work schedules,
and physical exercises.
Genetics largely influence the
variations between individuals, hence
there are people whom we recognise
as ‘larks’ (preferring to sleep early in the
night) and ‘night owls’ (ability to stay up
late into the night).
Genetics also determines the ability
of individuals to adapt to time cues in
the daily cycle, and hence the ability to
’tune their clocks’.
With age, this innate rhythm can also
change in its cycle length, commonly
reflected through changes in sleep
pattern as one grows older.
37
1. Jet Lag
This is a transient condition in which
the circadian rhythm is temporarily out
of synchronisation with the external
environment when a person travels
across several time zones rapidly.
Symptoms
Jet lag is a temporary condition which can be
managed.
Problems with Circadian Rhythm
It is important that you keep to
a regular sleep schedule, as this
maintains synchrony of the ‘body
clock’ with the demands of social
activities and duties. Any situation that
desynchronises the circadian rhythm
and the social rhythm will result in
sleep difficulties as well as problems in
maintaining alertness.
The most common causes of disruption
to circadian rhythm are jet lag, shift
work and circadian rhythm disorders.
38
The symptoms are usually daytime
fatigue and sleepiness, insomnia,
stomach upsets, moodiness and
feeling of unsteadiness. Some may
also experience chills, and others have
episodes of feeling hot and sweaty.
As our body clock runs slightly longer
than 24 hours, jet lag is worse when
we travel eastwards than when
we travel westwards. It is easier to
lengthen the day (delaying going to
bed) than to shorten it (trying to fall
sleep earlier). After travelling from
east to west, early waking is the main
problem, as opposed to difficulty falling
asleep when travelling from west to east.
Our circadian rhythm will eventually
synchronise with the local time at the
destination, at a rate of roughly one day
per hour of time difference.
Jet lag, shift work and circadian rhythm disorders
Tips for managing jet lag:
1. If you are able to, choose a
destination that involves flying
westwards.
2. Choose daytime flights to avoid
losing sleep.
3. Use sleeping aids such as blindfolds,
earplugs, and neckrests to help you
sleep during the flight.
4. Adjust to local time by keeping to
local routines at your destination,
such as taking meals and staying
awake when the locals do.
5. Try to keep awake during daytime.
Staying in a brightly lit environment
will facilitate the adjustment of the
body clock.
6. If necessary, naps should be short,
and planned so as not to affect
night time sleep.
7. Melatonin supplement may be
helpful for jet lag symptoms and
improving sleep when taken near
bedtime.
8. Exercise during the day.
9. Caffeine may help in maintaining
alertness.
10. Plan ahead for your journey and
make allowances for adjustments
where possible.
2. Shift Work
Shift workers are people who work
non-traditional hours, which may be
Flying westwards can cause less jet lag.
exclusively at night, or on rotating
shifts. They often face problems similar
to jet lag, even without crossing time
zones. The differences between their
‘day’ during which they are working,
and the natural day-night cycle have
resulted in a desynchronised circadian
rhythm. While some may have no
problems adapting to this demand,
many suffer from sleep problems.
They may experience insomnia, and
may not get enough sleep during
the day as the brain remains active,
culminating in sleep deprivation.
This eventually leads to wake time
sleepiness and impaired work
performance. They may have sleep
problems even on their days off.
The main objective of managing
shift work sleep problems is to try to
resynchronise the circadian rhythm
to the work schedule as quickly as
possible. In addition, we try to improve
39
on the quality and duration of sleep
at bedtime to reduce effects of sleep
deprivation. This is typically easier to
achieve for people who work regular
shift, and treatment is similar to that for
jet lag which is to adjust the body clock
to a new ‘daytime’.
What if I work rotating shifts?
The day before night shift: Get up
at your usual time and have meals as
usual. Take a two to three hour nap in
the late afternoon or early evening to
reduce your sleep debt before the start
of your duties.
During the shift: Take a power nap for
30 minutes if possible to reduce the
sleep debt. Avoid too long a nap as you
may have more difficulty getting into an
alert state.
Day after the night shift: If you have
to work another night shift, get six
to eight hours of sleep when you get
home. If you cannot get a long enough
sleep, nap in the late afternoon or early
evening as described earlier. If you do
not have to work nights again, catch
a short two to three hour nap after
you get home and stay awake till your
normal bedtime.
40
Adjust your body clock to manage shift work sleep
problems.
Tips to cope with rotating night
shifts:
1. Maintain a regular sleep routine
on normal work days and on rest
days.
2. Plan naps to reduce sleep debt
during night shift periods, and
catch up on sleep on rest days.
3. Eat properly and maintain
sufficient exercises to provide
cues for maintenance of
circadian synchronisation.
Jet lag, shift work and circadian rhythm disorders
Tips to sleep better during the day:
1. Maintain general sleep hygiene
principles. Avoid strenuous
exercises, caffeine and nicotine
four hours before bedtime.
2. On your way home from night
shift, use dark sunglasses to
reduce the effects from the bright
morning sunlight which may
influence the circadian rhythm.
3. Keep a conducive sleep
environment: Use dark curtains,
and earplugs if necessary.
4. Learn some relaxation skills
and avoid trying too hard to
get to sleep.
5. Avoid the temptation to defer
sleep to attend to personal
administrative or social tasks –
plan to do these after your
rest period.
6. If necessary, see your GP for shortterm prescription of sleeping aids.
Use these medications on an as
needed basis only.
3. Circadian Rhythm Disorders
These include the delayed sleep phase
syndrome (‘night owl’) or the advanced
sleep phase (‘morning lark’) syndrome.
Delayed sleep phase syndrome is more
commonly seen in teenagers and
may be related to a combination of
physiologic and environmental factors.
Developmental changes in the brain’s
circadian centres during adolescence
– poor sleep hygiene associated with
increasing amounts of school work
and the widespread use of computer
devices and smartphones late into the
night (which activate special receptors
in the eye) combine to delay the body’s
intrinsic sleep cycle resulting in the
affected patients being only able to
fall asleep in the early morning hours
and waking up late morning or early
afternoon regardless of whether they
are trying to fall asleep or not.
This can cause significant disruptions to
their schooling or work performance.
Scheduling enough time to sleep
is important and should be actively
prioritised and planned for. Good sleep
is essential to well-being, and allows
one to function efficiently and safely.
41
Advanced sleep phase syndrome is
more commonly seen in the middleaged and elderly. This may be due to
the natural shortening of our internal
sleep cycle with increasing age but may
also be contributed to by poor sleep
hygiene and changing sleep habits that
elderly people commonly experience.
Sufferers go to sleep very early in
the evening and wake up in the wee
hours of the morning and are unable
to go back to sleep again. Apart from
the inconvenience and the inability
to partake in evening social events,
insomnia in the early mornings, poor
quality sleep, daytime fatigue and
sleepiness and depression are common
associated complaints.
42
Treatment of Advanced or
Delayed Sleep Phase Syndrome
Consultation with a sleep specialist
is essential for accurate diagnosis
and to exclude other common sleep
conditions. An individualised treatment
plan can then be tailored accordingly
and this may include the following:
1. Optimise sleep hygiene and maintain
regular sleep-wake cycles, even on
weekends
2. Timed bright light exposure with
a special phototherapy device at
specific and individualised timings
3. Timed melatonin administration
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
Movement disorders in sleep
Movements during sleep are
quite common, especially
among children. They
usually represent a generally
benign and non-intimidating
condition.
These are disorders disrupting sleep
and have undesirable physical or verbal
behaviours or experiences. They occur
in association with sleep, in specific
sleep stages or in the sleep-wake
transition phases and are divided into
Primary and Secondary under the
terminology of Parasomnias.
EEG (Electroencephalogram) and
PSG (Polysomnogram) recordings
are essential to differentiate these
conditions.
Sleepwalking
Sleepwalking is common in children
between the ages of 5 and 12 but
can persist into adulthood or, rarely,
Primary Parasomnias
The major Primary Parasomnias
include Sleepwalking, REM Behaviour
Disorder (RBD), Restless Legs Syndrome
and Periodic Leg Movements, and
Nightmare Disorder and Sleep Terror
which are seen more in children.
These can sometimes be mistaken
for seizures. The characteristic
clinical features combined with
Sleepwalking, common in children, can persist
into adulthood.
43
begin then. It usually starts abruptly
within the first one-third of sleep and
generally lasts less than 10 minutes.
Sleepwalking episodes are usually
uneventful; injuries and violent
episodes are uncommon. Episodes can
be precipitated by sleep deprivation,
fatigue, other illnesses and sedatives/
hypnotics.
General precautionary measures should
be put in place when a person has
been diagnosed with sleepwalking.
The environment has to be made safe
i.e. lock doors and windows, remove
dangerous items and other hazards.
REM Behaviour Disorder (RBD)
RBD is an important REM sleep
parasomnia commonly seen in elderly
patients. The classic characteristic
feature is the loss of muscle tone
partially or completely during REM
sleep. There is also the appearance
of various abnormal motor activities
during sleep. You may experience
violent and dream-enacting behaviour
during REM sleep. This can cause
self-injury or injury to your bed partner.
RBD may be idiopathic or secondary
and most cases are now thought to
be secondary and associated with
neurodegenerative disorders.
RBD has been linked to
dopamine dysfunction based
on PET scan findings. REM sleep
without muscle atonia is the
most important finding in the
polysomnogram.
Violent or dream-enacting behaviour can happen in REM
Behaviour Disorder.
44
Movement disorders in sleep
Treatment
Treatment for RBD is usually initiated
with clonazepam at bedtime and doses
may have to be adjusted. It has been
shown to be beneficial in the long-term.
Drug discontinuation often results in
prompt relapse. Other drugs such as
tricyclic antidepressants and dopaminerelated medications have been tried
but effects are unpredictable.
Restless Legs Syndrome (RLS)
RLS is the most common movement
disorder. There is no diagnostic test
for RLS. The diagnosis rests entirely
on clinical features. RLS is a lifelong
sensory-motor neurological disorder
that often begins at a very young age
but is mostly diagnosed in the middle
or later years. It is more prevalent with
increasing age and then plateaus for
some unknown reason around age 85
to 90. In several surveys, it was found
that it tends to be more prevalent in
women. The disease is chronic and
progressive. There are studies indicating
that there is a possible genetic link.
The sensory manifestations of RLS
include intense disagreeable feelings
which are described as creeping,
crawling, tingling, burning, aching,
cramping, knife-like or itching
sensations. These usually occur
between the knees and ankles causing
an intense urge to move the limbs to
relieve these feelings.
Sometimes it can occur in the arms
or other parts, especially in advanced
stages. Most of the movements,
especially in the early stages, are noted
in the evenings when you are resting in
bed. In severe cases, movements may
be noted in the daytime when sitting or
lying down.
Women are more likely to have Restless Legs
Syndrome.
45
Periodic Leg Movements (PLMs)
At least 80% of RLS patients have
PLMs in sleep and sometimes in
wakefulness (PLMW).
Not all patients with PLMs have
RLS. PLMs cause excessive daytime
sleepiness but RLS commonly causes
insomnia.
The condition affects sleep profoundly
because there is not only a problem
of initiation of sleep but maintaining
sleep may also be difficult because of
PLMs.
Both RLS and PLMs generally undergo
similar investigations including blood
tests, nerve conductions, if necessary,
and a polysomnogram.
The causes of PLMs are uncertain.
Most are idiopathic (have no apparent
underlying cause) in nature but
secondary causes like obstructive
sleep apnoea, uremia, anaemia with
iron deficiency, neuropathies, diabetes
mellitus or certain drug withdrawals
can also cause this. The causes of RLS
are also uncertain.
The movements are repetitive in nature
and can involve one or both limbs. It
lasts about 2 seconds and occurs in
the earlier or middle stages of sleep. It
usually occurs in the legs and involves
upward movement of the big toe and
flexion of the ankle. It can sometimes
be seen at the knee and hip. Both legs
are usually involved and the same
movements can also occur in the arms.
46
Treatment
If the cause is known, this should be
treated. Caffeine, alcohol and nicotine
should be avoided before sleep.
Daily exercises and general physical
therapies like hot and cold packs and
massages can alleviate some of the
symptoms.
Drugs that can aggravate these
conditions should also be
avoided, if possible. These include
diphenhydramine, SSRIs, lithium and
betablockers.
Symptomatic treatment includes
the use of dopaminergic agents
like levodopa, dopamine agonists
like pramipexole, pergolide,
benzodiazepines like clonazepam,
Movement disorders in sleep
opioids and anticonvulsants like
Gabapentin.
Nightmare Disorder
This is usually seen in children. The
dreams are frightening and occur in
REM sleep and are associated with
profuse sweating and arousal. The heart
rate and respiratory rate are increased
and the child remembers the dream.
Sleep Terror
Sleep terror occurs during slow wave
sleep and usually between the ages of
5 to 7 years. There is a high incidence of
family history of sleep terror. Episodes
are characterised by extreme panic
and sudden loud terrified screaming
during sleep followed by physical
activities. They can injure themselves.
Recollection is partial or incomplete.
with chewing leads to abnormal wear
of the teeth, tooth pain, jaw muscle
pain or temporal headache. There is
usually no cause but can be associated
with stressful situations or anxiety
and seems to occur most frequently in
highly motivated or vigilant individuals.
Secondary Parasomnias
These are disorders of other organ
systems that may manifest during sleep.
Examples are seizures, respiratory
disorders, cardiac arrhythmias and
gastroesophageal reflux.
A good history and physical
examination and relevant investigations
should help exclude these.
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
Sleep-Related Bruxism
Though this has not been generally
thought to be a movement disorder,
it is generally discussed under this
because of its clinical features. It
is characterised by grinding or
clenching of the teeth during sleep
and associated with sleep arousals.
Contraction of muscles associated
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Sleepwalking
Sleepwalking is characterised
by complex behaviour
(walking) while asleep.
Nonsensical talking may
accompany this at times.
The eyes are usually open
with a characteristic ’glassy’
look that appears to have a
‘going through you’ kind of
appearance.
Sleepwalking appears to have a genetic link.
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It usually occurs in middle childhood
and adolescence but can persist into
adulthood. There appears to be a
genetic tendency.
Stage 1, 2 and 3 are described as NonRapid Eye Movement (NREM) sleep.
Rapid Eye Movement (REM) sleep is the
last cycle which is usually associated
with dreaming. There are 4 to 5
complete sleep cycles per night, each
cycle consisting of all three stages and
REM.
Sleepwalking
Sleepwalking usually occurs in the first
or second cycle during stage 3. It is not
usually seen during naps.
The person is not aware and has no
memory of his or her behaviour.
Causes
Genetic
It occurs more frequently in identical
twins. The risk is 10 times higher if a
first-degree relative has a history of
sleepwalking.
Environmental
The following factors can trigger
sleepwalking:
•
•
•
•
•
•
•
•
•
Associated Medical Conditions
• Arrhythmias
• Fever
• Gastroesophageal reflux
• Night time asthma
• Night seizures
• Obstructive sleep apnoea
• Psychiatric disorders
Symptoms
Episodes range from quiet walking
to agitated running. Eyes are open
with a glassy staring appearance. On
questioning, responses are slow with
simple thoughts. If returned to bed
Sleep deprivation
Chaotic sleep schedules
Fever
Stress
Magnesium deficiency
Alcohol intoxication
Sedative/hypnotic drugs
Stimulants
Antihistamines
Physiologic
Pregnancy and menstruation can
increase the frequency of sleepwalking.
Sleepwalkers will not remember the event.
49
without awakening, the person does
not usually remember the event.
Diagnosis
Usually no tests or exams are necessary
but a medical evaluation may be
done to rule out medical causes
of sleepwalking. A psychological
evaluation may also be done to exclude
excessive stress or anxiety as a cause.
Sleep tests may be done if the diagnosis
is still unclear.
Treatment
The following treatment options can
be undertaken for a person with
sleepwalking disorder:
General Measures
• Go to bed at the same time each
night.
• Attain adequate sleep.
• Avoid napping.
• Avoid stress, fatigue and sleep
deprivation.
• Moderate or relaxation exercises.
• Avoid any kind of stimuli prior to
bedtime.
• Environment must be safe from
harmful or sharp objects.
• Sleep on the ground floor and avoid
bunk beds.
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• Lock windows and doors.
• Remove obstacles in the room.
• Cover glass windows with heavy
drapes.
• Place alarm or bell on bedroom and
windows, if necessary.
Medical Treatment
The underlying cause should be
treated, for example, gastroesophageal
reflux, obstructive sleep apnoea,
seizures and other causes mentioned.
Medications may be necessary in the
following situations:
• The possibility of injury is real.
• Continued behaviours are causing
significant family disruption or
excessive daytime sleepiness.
• Other measures have proven to be
inadequate.
• Benzodiazepines have been shown
to be useful for 3 to 6 weeks and then
discontinued without recurrence
of symptoms but occasionally
frequency can increase briefly after
discontinuing the medication.
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
Sleepy driving
Sleepy driving is a serious
problem that can lead to car
crashes. Sleepiness causes
motor vehicle accidents because
it impairs concentration and
can lead to the driver falling
asleep at the wheel.
Microsleeps can overcome your best effort to
stay awake.
Important aspects of driving
impairment associated with
sleepiness are reaction time,
vigilance, attention, and information
processing. The exact prevalence
is not known in Singapore.
Sleepiness-related crashes is an
under-recognised problem and
may be categorised as fatigue and
inattention.
Although society today gives sleep
less priority than other activities,
sleepiness and performance
impairment are responses of
the human brain to sleep loss/
deprivation. There is currently
nothing that can reduce the human
need for sleep. Microsleeps, or
involuntary intrusions of sleep or
near-sleep, can overcome even the
best intentions to remain awake.
Accident Characteristics
A typical crash related to sleepiness
has the following characteristics:
• It occurs during late night/early
•
•
•
•
morning, or mid-afternoon.
The crash is likely to be serious.
A single vehicle leaves the roadway.
The driver does not attempt to
avoid a crash.
The driver is usually alone in the
vehicle.
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Risks for Sleepy Driving Crashes
• Sleep loss
The need for sleep varies among
people - sleeping eight hours per
24-hour period is common, and
seven to nine hours is needed to
optimise performance. Sleeping
less than 4 consolidated hours
per night impairs performance on
vigilance tasks. Acute sleep loss,
even the loss of one night of sleep,
results in extreme sleepiness.
The effects of sleep loss are
cumulative. Regularly losing one
to two hours of sleep a night can
create a ’sleep debt’ and lead to
chronic sleepiness over time.
Only sleep can reduce sleep debt.
Sleep loss can be work-related or a
lifestyle choice.
• Sleep quality
The quality of sleep is also
important. Sleep disruption and
fragmentation lead to inadequate
sleep and can negatively affect
functioning. Sleep fragmentation
can be caused by illness, including
untreated sleep disorders.
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Disturbances such as noise, young
babies, children, activity and lights,
a restless/snoring spouse, or jobrelated duties (e.g. workers who are
on call) can interrupt and reduce
the quality and quantity of sleep.
• Driving patterns
Late-night driving between
midnight and 6am, driving in the
mid-afternoon hours and driving
for longer periods without taking a
break.
• Use of sedating medications,
especially prescribed anxiolytic
hypnotics, tricyclic antidepressants,
and some antihistamines.
• Untreated or unrecognised sleep
disorders, especially sleep-related
breathing disorders, obstructive
sleep apnoea syndrome and
narcolepsy.
• Consumption of alcohol,
which interacts with and adds to
drowsiness.
A combination of these factors
increases crash risk substantially.
Sleepy driving
Sleepiness leads to slower reaction time.
Why Sleepy Driving Accidents
Happen
Sleepiness leads to:
Sleepiness leads to accidents because
it impairs human performances that
are critical to safe driving.
speeds, delay in reaction time
can have a profound effect on
crash risk.
• Reduced vigilance.
• It takes longer for information on
the roads to be integrated and
processed.
People can use physical activity and
dietary stimulants to cope with sleep
loss and mask their level of sleepiness.
However, when they sit still to
perform repetitive tasks like driving,
sleep comes quickly.
• Slower reaction time: At high
53
People at Highest Risk
• Young people (ages 16 to 29),
especially males
• Shift workers whose sleep is
disrupted by working at night or
working long or irregular hours
• People with untreated Sleep
Apnoea Syndrome (SAS) and
narcolepsy
Assessment for Chronic
Sleepiness
The Epworth Sleepiness Scale (ESS)
is an eight-item, self-report measure
that quantifies individuals’ sleepiness
by their tendency to fall asleep ’in
your usual way of life in recent times’
in situations like sitting and reading,
watching TV, and sitting in a car that
is stopped for traffic.
People with a score between 10 to14
are considered moderately sleepy,
whereas a score of 15 or greater
indicates severe sleepiness.
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Preventive Measures
To prevent sleepy driving and its
consequences, you need to know
the benefits of behaviours that
help you avoid becoming sleepy
while driving.
These include:
1. Getting sufficient sleep and
taking a short nap (15 to 20
minutes) when sleepy
2. Not drinking alcohol when
sleepy
3. Limiting driving between
midnight and 6am
4. Taking caffeinated drinks/food
e.g. coffee
5. Detection and treatment
of illnesses that can cause
excessive sleepiness like sleeprelated breathing disorders,
obstructive sleep apnoea
syndrome and narcolepsy
Sleep Disorders Unit
Singapore General Hospital | Tel: 6321 4377
Common sleep conditions
in infants, children and
adolescents
Sleep is Important
Sleep is an important part of healthy
growth and development in children,
just like nutrition and physical activity.
Contrary to the common perception
that sleep is only a passive state
during which the bodily processes
slow down and the body rests itself
at the end of the day, many active
physiological processes take place in
the body during sleep. Amongst these
are memory consolidation and growth
hormone secretion, which are important
physiological processes in children.
The paediatric sleep specialist is
concerned with both the quality and
quantity of sleep in children.
Children need sleep for growth and memory
consolidation.
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What can affect sleep?
Sleep-related disorders such as
obstructive sleep apnoea can disrupt a
child’s sleep.
Medical conditions in children, such
as uncontrolled asthma, allergic rhinitis
and eczema, can affect the quality and
duration of a child’s sleep.
School and social pressures, and the
increased usage of electronic devices
in this day and age, can also impact on
bedtime and the duration of sleep in
children and adolescents.
Why get a good night’s sleep?
Effects of poor sleep
Poor sleep can have various adverse
effects on a child’s health:
• Sleep deprivation can affect
daytime alertness, judgement,
memory, reaction time and motor
performance.
• The lack of sleep is associated with
behavioural problems and emotional
disturbances, which may reduce
the ability of the child to perform
optimally at school.
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• Decreased slow wave sleep (one of
the stages of sleep) is associated with
decreased growth hormone secretion
during sleep.
• Sleep deprivation is related to type
2 diabetes, obesity, hypertension,
metabolic syndrome, reduced
immunity and cardiovascular
problems.
Sleep Requirements in Infants
and Children
Sleep architecture (the pattern and
proportion of the different sleep stages
during sleep) and sleep requirements
evolve with the development and
maturation of the central nervous
system as a child progresses from
infancy through childhood and
adolescence, to adulthood.
Newborns spend an average of 14 to
17 hours in a 24-hour period asleep.
They may sleep for three to five
hours at a stretch (two to three hours
in breastfed babies), and then wake
for one to three hours in between.
Common sleep conditions in infants, children and adolescents
In toddlers, their sleep needs
averages between 11 to 14 hours
in a 24-hour period (including
daytime naps). The sleep duration
decreases further in pre-schoolers
to between 10 to13 hours. By
five years of age, most children stop
taking daytime naps.
School-going children should
be highly active and alert during
waking hours, and majority
require between 9 to 11 hours of
sleep at night.
At the onset of puberty, adolescents
may develop a two-hour phase
delay in their circadian rhythm
(‘body clock’), leading to a natural
tendency to fall asleep at later
times. Majority of adolescents
require an average of about eight to
ten hours of sleep.
There is no ‘golden rule’ to the exact
amount of sleep needed at different
ages, and there are often individual
variations in sleep requirements, sleep
patterns, as well as tolerance to sleep
deprivation. In general, the duration of
sleep is sufficient if the child feels
well-rested on waking spontaneously,
and is able to function normally
throughout the day.
Some of the signs of insufficient sleep
include:
• Excessive daytime sleepiness
• Mood disturbances
• Behavioural problems such
as inattention, hyperactivity,
oppositional behaviour and poor
impulse control
• Impaired cognitive functioning such
as poor concentration, impaired
vigilance, delayed reaction time and
learning problems
Good Sleep Hygiene and
Practices
The following advice can help children
achieve better sleep:
• Maintain a consistent sleep and wake
time daily, including school days and
non-school days.
• Avoid using the bed for any other
activity (e.g. reading, watching
television, playing games on
personal electronic devices, eating)
than sleeping.
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• Avoid using the bedroom for time-out
•
•
•
•
•
•
•
58
or punishment.
Ensure that the bedroom is conducive
for sleeping. Keep it dim, cool and
quiet.
Establish a regular relaxing routine
before bedtime (e.g. brushing teeth,
changing into pyjamas, reading of a
story).
Go to bed only when tired or sleepy,
rather than spending too much time
awake on the bed. If your child is
unable to fall asleep after 20 minutes,
consider letting him get out of bed to
do some low stimulation activity (e.g.
quiet reading) and then returning to
bed later.
Avoid caffeine (e.g. coffee, tea,
chocolate, cola and soda drinks) and
nicotine (exposure to environmental
tobacco smoke) at least four to six
hours before bedtime.
Avoid going to bed with a full
stomach or when too hungry.
Avoid stimulating activities before
sleep (e.g. watching of exciting/
frightening television programs,
playing of games on personal
electronic devices).
Regular exercise is encouraged, but
avoid exercise or strenuous activities
at least four hours before bedtime.
Do not use the bed for other activities other than
sleeping.
Sleep Advice for Parents of
Newborns and Infants
The sleep and wake times of newborns
and infants are often influenced by their
need to be fed or changed.
It is important that parents understand
how newborns and infants sleep, so that
they can set realistic expectations.
• Babies do not understand what is
‘sleeping through the night’, and
many do not do so until they are more
than 3 to 6 months old.
Common sleep conditions in infants, children and adolescents
• Every baby is different; your baby may
have different sleep patterns from
other babies and still be normal and
healthy.
• Your baby will begin to sleep for
longer periods of time at night as he/
she grows and develops over time.
All babies wake up spontaneously at
least a few times during the night.
They may require soothing and
intervention from caregivers to fall
back to sleep in the first couple of
months. At the age of three to six
months onwards, most will have the
ability to self-soothe themselves back
to sleep.
Parents with newborns and infants may
consider the following advice to help
their babies develop the ability to selfsoothe (It is never too early to start!):
• Put your baby to the crib/bed
drowsy but still awake, so that he/she
can learn to fall asleep on his/her own.
• Avoid breastfeeding or bottle
feeding your baby to sleep, so that
he/she does not require this to fall
asleep. Some parents find gentle
rhythmic patting of their babies
helpful in settling them to sleep, but
it is best to stop the patting when the
baby is quiet and about to fall asleep.
• Learn to identify signs of sleepiness
Babies, before 3 to 6 months old, do not sleep
through the night.
in your baby. Babies may express
their need to sleep in different ways.
Some babies fuss or cry, some rub
their eyes or pull their ears, others lose
focus in ongoing play or activity.
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• Avoid picking your baby up
immediately each time he/she
cries or fusses in the night. As long
as safety is not a concern, allow your
baby to try to fall back to sleep on his/
her own first. If you need to check on
your baby in the night, keep it brief,
and avoid turning on bright lights and
engaging/stimulating activities. When
feeding or changing your baby during
the night, do so in a quiet and calm
manner.
• Avoid night feedings after the age
of 6 months. Night feedings are not
necessary for growth after the age of
6 months, but may potentially disrupt
sleep.
• Wrapping newborns snugly with
a thin baby blanket may help them
feel more secure and reduce ‘startles’
during sleep. Always check that the
wrapping is not too tight, and that the
baby’s breathing is not obstructed.
• Engage in play and stimulating
activities during your baby’s wake
period, but keep the environment
dimmer and quieter with less activity
as evening approaches, to help your
baby sleep better and longer during
the night.
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Wrap newborns snugly to help them sleep better.
Behavioural Insomnia in
Childhood (BIC)
Insomnia, which is the inability to initiate
and/or maintain sleep, may not only
affect children, but also their parents
and the whole household.
There are many possible causes
of insomnia in children, including
behavioural insomnia of childhood
Common sleep conditions in infants, children and adolescents
(which is discussed below), delayed
sleep phase disorder (common in
adolescents due to a ‘shift in their body
clock’ at puberty), medical conditions
(causing pain, itching or coughing in
the night), psychological conditions
(e.g. anxiety, depression, stress) and
medications.
This section will discuss behavioural
insomnia of childhood, which can
be further classified into sleep-onset
association type, limit-setting type,
or combined. If you suspect that
your child has insomnia, consult a
doctor who may refer your child to a
paediatric sleep specialist.
1. Sleep-Onset Association Type BIC
A child with sleep-onset association
BIC relies on a specific stimulation
(object or setting) for the initiation of
sleep at bedtime, or to fall back to sleep
following an awakening in the night.
Associations that are highly demanding
or disruptive to the caregivers are
considered negative sleep onset
associations (e.g. prolonged rocking,
night feedings inappropriate for age).
How common is it?
This is common, and estimated to affect
between 25 to 50 percent of infants at
the age of 6 to 12 months of age, and 15
to 20 percent of toddlers.
Have a good sleep routine with positive sleep
associations.
What to look out for?
The child with sleep-onset associations
often presents with frequent night
awakenings as he/she is unable to
self-soothe back to sleep after a
spontaneous night awakening. The child
may continue to cry and stay awake for
prolonged periods until the caregiver
intervenes to provide the association
required for him/her to fall back to sleep.
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Risk factors
Factors that may increase the
likelihood of night awakenings include
breastfeeding, co-sleeping, colic,
acute illness, changes in the sleep
environment, a difficult temperament,
parental anxiety, and when the child
has just achieved a certain motor or
cognitive developmental milestones (e.g.
pulling to stand, separation anxiety).
Management
Management of sleep-onset association
type BIC includes establishing a good
sleep routine, and the use of positive
sleep associations: e.g. a comforting
object (stuffed toy or used mother’s shirt)
that the child can bring to bed with him/
her each night.
There is no ‘best’ method to help a
child fall asleep independently, but the
key is to be ‘consistent and persistent’
every night, especially if more than one
caregiver is involved. Often, once the
child is able to fall asleep independently
at bedtime, he/she is more likely to
be able to self-soothe to sleep during
spontaneous night awakenings.
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Some methods that have been used
include:
1. Extinction – Putting the child to bed
at a fixed time and ignoring his/her
cries until a specific ‘wake’ time. This
method is not recommended for
infants below the age of 6 months,
and may be emotionally draining.
Parents should be prepared for a
‘post-extinction burst’ (a period of
worsening before improvement) in
some children.
2. Graduated extinction – This is a
‘gentler’ method, where you can
respond to your child briefly each
time he/she calls (after being put
to bed), but only after progressively
longer periods of time e.g. 5 minutes,
then 10 minutes, and then 15 minutes
until he/she falls asleep. This method
is likely to take longer to work, but is
less emotionally taxing.
3. Fading of adult intervention –
Establish a bedtime routine before
sleep, and gradually increase the
physical distance between you and
your child while he/she is falling
asleep (sit by the crib or bed, and
move the chair slightly further away
each night, until out of sight of the
child). This method is also likely to
take longer but is less emotionally
taxing.
Common sleep conditions in infants, children and adolescents
2. Limit-Setting Type BIC
In limit-setting type BIC, inadequate
enforcement of bedtime limits by
parents result in the child delaying
bedtime or refusing to go to bed.
How common is it?
Bedtime resistance is estimated to
be present in 10 to 30 percent of
preschoolers. About 15 percent of
children aged 4 to 10 years old may
still have significant limit-setting sleep
issues.
What to look out for?
Bedtime stalling behaviours are
attempts by the child to delay bedtime
(e.g. requests for another book, another
hug, another drink of milk). Some
children may also exhibit bedtime
refusal behaviour: such as refusal to get
ready for bed, or refusal to stay in bed.
Some children may indicate night time
fears in order to stall bedtime.
In some situations, parents do not set
appropriate limits or are inconsistent in
their limit-setting (e.g. allowing the child
to fall asleep while watching television,
or to fall asleep on the parent’s bed).
Other daytime behavioural problems
and limit-setting difficulties may also be
present in these children.
Risk factors
Factors that increase the risk of
limit-setting disorders include the
child sharing the parent’s bedroom,
conflicting parental disciplinary styles
and family tension.
Management
Management includes good sleep
practices mentioned earlier, specifically
setting a fixed bedtime, reviewing sleep
schedules (e.g. avoid late afternoon
naps), and consistent parental limitsetting.
Parents should aim to establish a set
bedtime that coincides with the child’s
natural sleep time. The method of
’bedtime fading’ may be practised,
where the bedtime is initially set at the
current bedtime, and brought forward
gradually to the desired bedtime, to
reduce struggles between bedtime and
sleep onset.
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Clear bedtime rules need to be set
with the child (e.g. staying in bed, not
calling out for parents), and ignoring
complaints about bedtime (e.g. ‘I am not
tired yet’). Check on the child briefly if
needed, provide reassurance and return
the child to bed if he/she gets out of
bed. A transient worsening of behaviour
may occur in some children at the
beginning. Caregivers are encouraged to
be consistent and firm each time.
Positive reinforcement (e.g. sticker charts
and small rewards) may help motivate
the child.
Parasomnias in Children
Parasomnias are unpleasant or
undesirable events that intrude into
sleep. The common parasomnias in
children are nightmares, confusional
arousals, sleep terrors and sleepwalking.
With the exception of nightmares,
parasomnias usually occur in slow wave
sleep (within the first few hours of the
night after the child falls asleep), and
there is often no recollection of the
event the next morning.
These events can occur in otherwise
healthy children, but may occur more
frequently during episodes of acute
illness and/or fever, stress, sleep
deprivation or in association with any
disorder that disrupts sleep.
This section will focus on some of these
parasomnias in more detail:
1. Confusional Arousals
Set clear and consistent bedtime rules for your child.
64
Confusional arousals consist of confused
behaviour during and following arousals
from sleep in the night, and/or upon
attempted awakening from deep sleep
in the morning.
Common sleep conditions in infants, children and adolescents
How common is it?
Confusional arousals are present in
5 to 15 percent of children and are
usually benign in nature. They usually
start before 5 years of age and peak in
frequency during mid-childhood before
spontaneous remission. There may be a
family history of confusional arousals or
sleepwalking.
What to look out for?
Episodes of confusional arousals are
usually sudden, and may be startling.
The child may appear to be awake but is
disorientated and will be slow in speech
and mentation, responding poorly to
commands. The child may sit up in bed,
moan or whimper inconsolably, and
say words like ‘Go away!’ , ‘No!’ or may
even be more bizarre like talking to a
lamp. The episode usually lasts for a
few minutes to half an hour, sometimes
longer.
2. Sleepwalking (Somnambulism)
Sleepwalking consists of a series of
complex behaviours. It is usually
initiated during arousal from sleep and
culminates in walking around with
an altered state of consciousness and
impaired judgement.
How common is it?
The onset of sleepwalking is usually
between 4 to 6 years of age. About 15 to
40 percent of children have sleepwalked
on at least one occasion, with 3 to 4
percent having frequent (weekly or
monthly) episodes. Episodes usually
decrease during adolescence. In children
who sleepwalk, a third of them continue
to sleepwalk for 5 years, while 12 percent
continue to do so for 10 years. There may
be a family history of sleepwalking.
What to look out for?
Episodes of sleepwalking usually
begin with the child sitting up in
bed and looking around confused,
before walking. It can involve routine
behaviours (e.g. unlocking the door,
walking out of the room) or more
inappropriate behaviour (e.g. urinating
into a waste paper basket). The child
may sometimes speak, but the speech
is usually meaningless. The child usually
appears to be awake with the eyes open
with a confused ‘glassy’ stare.
The child may then return to sleep
on his/her bed, or lie down at an
inappropriate site to sleep. The child is
usually very difficult to arouse during an
episode of sleepwalking, and will appear
confused and disorientated if awoken.
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3. Sleep Terrors (Night Terrors)
Sleep terrors are characterised by sudden
arousals from sleep with behavioural
manifestations of intense fear.
How common is it?
Typical onset of sleep terrors is between
2 to 4 years of age and tends to
decrease in frequency as the child grows
older. It rarely persists beyond puberty.
Usually more males than females are
affected, and a history of sleep terrors
in family members may be present.
It is estimated to affect 3 percent of
prepubertal children, and one percent
of adults.
What to look out for?
The event is often of sudden onset.
The child sits up in bed and screams
in fear, looking tensed with symptoms
of flushing, sweating, fast breathing
and increased heart rate. The child
is often inconsolable and attempts
to pacify him/her may worsen the
reaction. If awoken, the child will appear
disorientated and confused. Episodes
usually last for a few to 5 minutes, with
the child returning to sleep on his/her
own thereafter.
66
Sleep terrors may be confused with
another more common parasomnia –
nightmares. In contrast to night terrors,
nightmares tend to occur in the last one
third of the night (during a sleep stage
known as rapid eye movement sleep or
‘dream sleep’), and if awoken, the child
is orientated and able to recall events
vividly.
Mild cases of parasomnias are often benign
and self-limiting.
Common sleep conditions in infants, children and adolescents
Management of
Parasomnias
In majority of cases,
reassurance and education
of the child and parents
will suffice.
Parents should be
Maintain good sleep hygiene and practices to help manage
encouraged to maintain
parasomnias.
good sleep hygiene and
practices, specifically a consistent
Obstructive Sleep Apnoea (OSA)
bedtime routine and schedule for
in Children
the child.
Obstruction sleep apnoea is a condition
Prevention of physical injuries is
where there is recurrent ‘blockage’ of the
important in sleepwalking (e.g. installing upper airway during sleep, leading to
gates at the top of the stairway, locking
reduced airflow to the lungs and sleep
of windows and the main door). Parents
disruption. Snoring is an important
should be advised to guide the child
symptom of obstructive sleep apnoea,
slowly and calmly back to the bed
but not all children with snoring will
during a sleepwalking episode without
have obstructive sleep apnoea. Children
waking him/her. In children where these
with habitual snoring but no evidence
episodes are recurrent, a scheduled
of compromised breathing and sleep
awakening just before the usual time of
disruption have ‘primary snoring’.
the first episode on a nightly basis for a
few weeks may be effective.
How common is it?
It is estimated that overall, 3 to 12
Causes of fragmented sleep (e.g.
percent of children have habitual
obstructive sleep apnoea, periodic
snoring, and 1 to 3 percent of children
leg movement disorder) may worsen
have snoring with obstructive sleep
parasomnias, and if suspected, should
apnoea. Boys and girls are equally
be identified and treated. Medications
affected. The peak age is between
are rarely needed.
67
4 to 7 years of age, usually in children
with enlarged tonsils and/or adenoids.
There is a second peak seen in older
children above 8 years old who tend to
be obese.
Causes
The two most important causes of
obstructive sleep apnoea in children
are enlarged tonsils and/or adenoids,
and obesity.
Risk factors
Other children at risk for obstructive
sleep apnoea include children with
neuromuscular (central nervous system
and muscle) disorders, abnormalities in
the jaw and/or face, Trisomy 21 (Down
syndrome), and those with a family
history of sleep and breathing disorders.
What to look out for?
Some of the symptoms suggestive of
obstructive sleep apnoea include:
• Snoring
• Apnoea (pauses in breathing during
sleep)
• Snorting, gasping noises during sleep
68
• Laboured breathing during sleep,
•
•
•
•
•
•
•
•
•
•
•
with ‘sucking in’ of the chest
Unusual sleeping positions, such as
hyperextending the neck to breathe
better, sitting up, or propped up
with many pillows
Restlessness and frequent
awakenings during sleep
Sweating during sleep
Mouth breathing in the day or
during sleep
Cyanosis (blue discolouration of the
lips/face)
Difficulty waking in the morning
Feeling unrefreshed after an
overnight sleep
Morning headaches
Irritability or aggressive behaviour
during the day
Learning difficulty
Excessive sleepiness during the day
Complications
Some of the complications of untreated
obstructive sleep apnoea include:
• Learning and/or behavioural
problems
• Poor growth
• Diabetes, obesity, hypertension, heart
failure, stroke
• Death (in very severe, untreated cases
– rare)
Common sleep conditions in infants, children and adolescents
Diagnosis
Clinical history and physical examination
are not sufficiently reliable to
differentiate primary snoring from
obstructive sleep apnoea. If the doctor
suspects that your child has obstructive
sleep apnoea, he will refer your child to
a paediatric sleep specialist for review,
and for an overnight polysomnography
(sleep study).
Your child will be admitted overnight
to a single room in a sleep laboratory,
where his/her sleep and breathing
will be monitored and recorded
continuously during sleep. There will be
sensors placed on your child’s head and
body, and elastic bands placed around
his/her chest and abdomen, connected
by wires to a computer system that
records the data. This is not a painful
procedure and most children will be
able to fall asleep after they get used
to the setup. A caregiver is allowed to
stay overnight with the child during the
study.
Treatment
The treatment of obstructive sleep
apnoea in children depends on the
underlying cause.
In children with enlarged tonsils
and/or adenoids, surgery would be
recommended.
For more information, please refer to our
booklet: ‘Up Close: Get the answers to
common Ear, Nose and Throat Conditions’
for more details on surgical treatment,
including adenotonsillectomy (section:
Common ENT conditions among Children
– Snoring in Children and Tonsils &
Adenoids).
In children who are obese, weight
loss measures such as healthy eating
and regular exercise are encouraged.
They may also be referred to
paediatric specialists for weight
management programmes and to
screen for conditions such as diabetes,
hypertension and hyperlipidaemia.
In some children where surgery is not
an option or if they continue to have
significant residual obstructive sleep
apnoea after surgery, they may be
recommended the use of Continuous
Positive Airway Pressure (CPAP) during
sleep.
69
The CPAP set-up consists of a face mask
connected by a tubing to a machine
that generates and delivers a positive
pressure. This pressure helps to keep
the upper airway of your child open
during sleep. Children who are treated
with CPAP will need to be managed by
a paediatric sleep specialist, who will
recommend regular follow-up checks
and sleep studies.
Besides the treatments mentioned
above, a small group of children may
benefit from an orthodontic assessment
and other procedures or surgeries for
their sleep apnoea.
Respiratory Medicine Service
KK Women’s and Children’s Hospital
| Tel: 6294 4050
70
Services available at SingHealth Institutions
Singapore General Hospital
Sleep Disorders Unit
SGH Sleep Disorders Unit (SDU) is the
largest and most complete sleep unit
in Singapore. It is a multidisciplinary
unit comprising neurologists,
respiratory physicians, ENT (Ear, Nose
and Throat) surgeons, psychiatrists,
psychologists, sleep technologists
and respiratory therapists. It is also
the first adult sleep unit in Singapore
to achieve international accreditation
by The Thoracic Society of Australia
and New Zealand.
We offer the most comprehensive
range of inpatient and outpatient
services for the evaluation, treatment
and education of patients with
sleep disorders in Singapore. Sleep
disorders include sleep disordered
breathing, obstructive sleep apnoea,
snoring, obesity hypoventilation
syndrome, parasomnias, nocturnal
epilepsy, REM disorders, leg
movements disorders and insomnia.
71
We comprise a Sleep Disorders Clinic
for outpatient consultation services
and patient rooms for performing
sleep studies. Our sleep studies are
very thorough with measurements of
brain waves, respiratory pattern and leg
movements for example and are fully
attended by sleep technologists.
The following services are available:
Sleep Study
• Overnight Diagnostic
Polysomnogram (PSG) or
Overnight Sleep Study
This is the most common type
of sleep study, primarily used
to diagnose sleep apnoea and
parasomnia.
• Home Sleep Study
• Positive Airway Pressure (PAP)
Titration Sleep Study
either Continuous Positive Airway
Pressure (CPAP) or BiLevel
Positive Airway Pressure (BIPAP)
The sleep study is used to determine
the necessary PAP pressure required
to abolish the sleep apnoea and
to determine effectiveness of PAP
therapy.
72
• Multiple Sleep Latency Test
(MSLT) This test is used to aid in
diagnosis of narcolepsy and to
measure the severity of daytime
sleepiness. It is performed in the day
following an overnight diagnostic
PSG.
• Maintenance of Wakefulness Test
(MWT)
• Full EEG Overnight
Polysomnogram (PSG)
Outpatient Services
• Outpatient Consultation Clinic
Sleep physicians conduct a
dedicated clinic for diagnosis,
evaluation and treatment of sleep
disorders.
• Positive Airway Pressure Therapy
Services
Education and counselling services
regarding use of Positive Airway
Pressure therapy.
• Cognitive Behavioral Therapy
(CBT)/ Psychotherapy
Services available at SingHealth Institutions
Sleep Disorders Unit
Dr Toh Song Tar (Director)
Consultant
Department of Otolaryngology
(Ear, Nose & Throat)
Dr Leow Leong Chai
Consultant
Department of Respiratory and
Critical Care Medicine
Dr Ong Thun How
Senior Consultant
Department of Respiratory and
Critical Care Medicine
Dr W.S. Shahul Hameed
Consultant
Department of Neurology
Assoc Prof Pavanni Ratnagopal
Senior Consultant
Department of Neurology
Dr Anne Hsu
Senior Consultant
Department of Respiratory and
Critical Care Medicine
Assoc Prof Ng Beng Yeong
Senior Consultant
Department of Psychiatry
Dr Tan Keng Leong
Senior Consultant
Department of Respiratory and
Critical Care Medicine
Dr Han Hong Juan
Consultant
Department of Otolaryngology
(Ear, Nose & Throat)
Dr Sin Gwen Li
Consultant
Department of Psychiatry
Mr Kevin Beck
Principal Psychologist
Department of Psychiatry
Mr Christopher Gabriel
Senior Principal Neuropsychologist
Department of Neurology
Ms Kinjal Doshi
Principal Clinical Psychologist
Department of Neurology
For enquiries, please contact:
Tel: 6321 4377
Fax: 6224 9221
www.sgh.com.sg
73
• We also partner family physicians
and paediatricians to facilitate the
medical care and management of
our patients at the community level
KK Women’s and
Children’s Hospital
Respiratory Medicine
A key referral centre in Singapore for
breathing and sleep-related disorders,
our Respiratory Medicine Service cares
for a wide range of conditions affecting
newborns to 16-year-olds. We lead two
national programmes:
• The National High Risk Asthma
Shared Care (NASC) programme,
also known as Singapore National
Asthma Programme (SNAP)
• The evaluation of severely obese
children with Obstructive Sleep
Apnoea (OSA)
74
Range of Conditions:
• General respiratory disorders
• Asthma
• Chronic/congenital lung diseases
• Respiratory infections
• Sleep-related breathing disorders
• General sleep disorders
Range of Services:
• Pulmonary assessment.
We have a complete pulmonary
function laboratory where we can
perform spirometry, lung volume,
diffusion, exhaled nitric oxide, and
bronchoprovocation studies. We also
conduct cardiopulmonary exercise
tests for children.
• Skin allergy testing.
This complements the evaluation of
an atopic child with asthma.
• Paediatric flexible bronchoscopy.
Services available at SingHealth Institutions
• Video polysomnography and
mean sleep latency tests.
Our Sleep Disorders Centre evaluates
sleep disorders ranging from
sleep-related breathing disorders,
parasomnias, hypersomnias, and
periodic limb movement disorders.
For enquiries, please contact:
Tel: 6294 4050
Fax: 6293 7933
www.kkh.com.sg
Senior Consultants
Dr Teoh Oon Hoe (Head)*
Prof Chay Oh Moh
Adj Assoc Prof Anne Goh Eng Neo*
Dr Biju Thomas*
Consultants
Dr Arun Pugalenthi*
Dr Petrina Wong*
*Accepts referrals for sleep disorders
75
Acknowledgements
Dr Toh Song Tar
Consultant
Department of Otolaryngology
(Ear, Nose & Throat)
Director, Sleep Disorders Unit
Singapore General Hospital
Dr Ong Thun How
Senior Consultant
Department of Respiratory and Critical
Care Medicine
Singapore General Hospital
Dr Tan Keng Leong
Senior Consultant
Department of Respiratory and Critical
Care Medicine
Singapore General Hospital
Assoc Prof Ng Beng Yeong
Senior Consultant
Department of Psychiatry
Singapore General Hospital
Assoc Prof Pavanni Ratnagopal
Senior Consultant
Department of Neurology
Singapore General Hospital
76
Dr Victor Kwok
Consultant
Department of Psychiatry
Singapore General Hospital
Dr Han Hong Juan
Consultant
Department of Otolaryngology
(Ear, Nose, Throat)
Singapore General Hospital
Dr Leow Leong Chai
Consultant
Department of Respiratory and Critical
Care Medicine
Singapore General Hospital
Dr W.S. Shahul Hameed
Consultant
Department of Neurology
Singapore General Hospital
Dr Shaun Loh
Registrar
Department of Otolaryngology
(Ear, Nose & Throat)
Singapore General Hospital
Acknowledgements
Adj Assoc Prof Anne Goh Eng Neo
Head and Senior Consultant
Allergy Service
Department of Paediatric Medicine
KK Women’s and Children’s Hospital
Dr Teoh Oon Hoe
Head and Senior Consultant
Respiratory Medicine Service
Deputy Head, Department of Paediatric
Medicine
KK Women’s and Children’s Hospital
Dr Petrina Wong
Consultant
Respiratory Medicine Service
Department of Paediatric Medicine
KK Women’s and Children’s Hospital
77
www.singhealth.com.sg
For enquiries, consult your GP/Family Doctor or contact us at:
SingHealth Hospitals
Tel: (65) 6222 3322
Tel: (65) 6225 5554
www.sgh.com.sg
www.kkh.com.sg
Tel: (65) 6472 2000
www.sengkanghealth.com.sg
www.ah.com.sg
National Specialty Centres
Tel: (65) 6436 8000
www.nccs.com.sg
Tel: (65) 6436 7800
www.nhcs.com.sg
Tel: (65) 6227 7266
www.snec.com.sg
Tel: (65) 6324 8802
Tel: (65) 6357 7153
www.ndcs.com.sgwww.nni.com.sg
Primary Healthcare
Community Hospital
Tel: (65) 6236 4800
polyclinic.singhealth.com.sg
For international enquiries:
24-hr Hotline: (65) 6326 5656
Fax: (65) 6223 6094
Email: [email protected]
First printed January 2013. Reprint March 2016. Reg. No.: 200002698Z